Exploring the ocean microbiome: quantified cobalamin production in pelagic bacteria using liquid chromatography and mass spectrometry

Abstract

Cobalamin, also known as Vitamin B 12 , is an essential part of life. It plays a crucial role in the ocean, regulating the metabolic activities of oceanic microbes, which in turn play dynamic roles in carbon cycles and subsequent atmospheric regulation. This research quantifies cobalamin production in two species of bacteria under high and low carbon environments, and in environments enriched with two compounds that may originate from other microbial community members and indicate cobalamin stress. Using liquid chromatography and mass spectrometry, this research shows that for most bioavailable cobalamin, both R. pomeroyi DSS-3 and Sulfitobacter sp. SA11 produce more but statistically insignificant cobalamin molecules per cell when grown in high carbon environments, as opposed to when grown in carbon starved conditions. When bacteria were grown in enriched environments, overall cobalamin production was unaffected by stress signaling compounds, although adenosylcobalamin showed significant change in production. Overall, the figures were statistically inconclusive due to small sample size and high intra-sample variation. However, these findings lay groundwork for further research. An important symbiosis involving cobalamin between primary producers and subsections of bacteria and archaea has recently been the subject of metabolomics and proteomics research. The results from this paper provide valuable data for more analysis in this area, by supplying precedent for growing organisms in diluted Seawater Tryptone, and quantitative values of cobalamin production in normal conditions for use in cobalamin models. The findings of this paper highlight both the importance of cobalamin in the ocean microbiome, and the complexity of the microbial interactions in the ocean.